Probe structure

ABSTRACT

A probe structure for inspecting characteristics of a connector having at least one terminal includes a plunger, a coaxial probe, a flange, a housing, and a spring. A first end portion of the housing and the flange are configured to restrict rotation of the housing in the circumferential direction in a state in which the first end portion of the housing is fitted into the through-hole of the flange. Thus, inspection of characteristics of the terminal of the connector can be performed with higher accuracy.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.16/449,177 filed Jun. 21, 2019, which claims benefit of priority toInternational Patent Application No. PCT/JP2017/034787, filed Sep. 26,2017, and to Japanese Patent Application No. 2016-249796, filed Dec. 22,2016, the entire contents of each are incorporated herein by reference.

BACKGROUND Technical Field

The present disclosure relates to a probe structure for a connector.

Background Art

To date, probe structures for inspecting characteristics of a connector,which is an inspection target, have been disclosed as described, forexample, in International Publication No. 2016/072193.

The probe structure described in International Publication No.2016/072193 is a probe structure for inspecting characteristics of acoaxial connector, in particular, for inspecting characteristics of amultipole connector having a plurality of terminals so that theconnector can pass a plurality of signals. The probe structure describedin International Publication No. 2016/072193 includes a plurality ofcenter conductors that can simultaneously contact the plurality ofterminals of the multipole connector.

SUMMARY

For a probe structure for a connector, improvement of the accuracy ofinspection of characteristics of terminals is required. With the probestructure described in International Publication No. 2016/072193, withwhich the plurality of center conductors simultaneously contact theplurality of terminals, displacement between the terminals and thecenter conductors tends to occur, and the accuracy of inspection ofcharacteristics tends to decrease. Regarding probe structures, includingthe one described in International Publication No. 2016/072193,development of technology that allows inspection of characteristics ofterminals to be performed with higher accuracy is required.

Accordingly, the present disclosure provides a probe structure thatallows inspection of characteristics of terminals of a connector to beperformed with higher accuracy.

The probe structure according to the present disclosure is a probestructure for inspecting characteristics of a connector including atleast one terminal. The probe structure includes a plunger that includesa groove portion to which the connector is to be fitted; a coaxial probethat is inserted into the plunger and that allows a conductor pin to beexposed at a position corresponding to the terminal of the connectorthat is fitted into the groove portion of the plunger; and a flange thatis fixed to an apparatus for inspecting the characteristics at aposition that is spaced apart on a side opposite to a side on which theconducting pin is exposed with respect to the plunger. The flange has athrough-hole into which the coaxial probe is inserted. The probestructure also includes a housing that includes a first end portion anda second end portion and that extends toward the plunger whilesurrounding the coaxial probe. The first end portion is fitted into thethrough-hole of the flange from a side opposite to a side on which theplunger is disposed, and the second end portion is attached to theplunger. The probe structure further includes a spring that is attachedto a portion between the plunger and the flange, that is disposed at aposition surrounding the housing, and that urges the plunger in adirection away from the flange. The first end portion of the housing andthe through-hole of the flange have outer shapes that restrict rotationof the housing in a circumferential direction in a state in which thefirst end portion of the housing is fitted into the through-hole of theflange.

With the probe structure according to the present disclosure, it ispossible to inspect characteristics of terminals of a connector withhigher accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

These aspects and features of the present disclosure will be elucidatedfrom the following description of preferred embodiments with referenceto the attached drawings.

FIG. 1 is a schematic perspective view of a probe structure according toa first embodiment;

FIG. 2 is a partial schematic perspective view of the probe structure;

FIG. 3 is a partial schematic perspective view of the probe structure;

FIG. 4 is a schematic perspective view of a plurality of coaxial probesinserted into a plunger;

FIG. 5 is a schematic perspective view of one of the coaxial probes;

FIG. 6 is a schematic perspective view illustrating the relationshipbetween the coaxial probes and terminals of a multipole connector;

FIG. 7 is a partial schematic longitudinal sectional view illustrating afitting portion of the plunger;

FIG. 8A is a schematic sectional view illustrating a method ofinspecting characteristics of terminals by disposing a multipoleconnector in a groove portion;

FIG. 8B is a schematic sectional view illustrating a method ofinspecting characteristics of the terminals by disposing the multipoleconnector in the groove portion;

FIG. 9 is an exploded perspective view of the probe structure;

FIG. 10 is an exploded perspective view of the probe structure;

FIG. 11 is a schematic longitudinal sectional view of the probestructure;

FIG. 12A is a schematic perspective view illustrating a fitted state inwhich a housing and a flange are fitted to each other;

FIG. 12B is a schematic perspective view illustrating an unfitted statein which the housing and the flange are not fitted to each other;

FIGS. 13A-13C schematically illustrate the positional relationship amongcomponents when positioning a connector by disposing the connector inthe groove portion of the plunger;

FIGS. 14A-14C schematically illustrate the positional relationship amongthe components when positioning the connector by disposing the connectorin the groove portion of the plunger;

FIGS. 15A-15C schematically illustrate the positional relationship amongthe components when positioning the connector by disposing the connectorin the groove portion of the plunger;

FIG. 16 is a schematic longitudinal sectional view of a second side wallof the groove portion;

FIG. 17 is a graph representing the relationship between the frictioncoefficient and the inclination angle of the second side wall;

FIG. 18 is a schematic perspective view of a probe structure accordingto a second embodiment; and

FIG. 19 is a schematic perspective view of a probe structure accordingto a third embodiment.

DESCRIPTION OF EMBODIMENTS

According to a first aspect of the present disclosure, there is provideda probe structure for inspecting characteristics of a connectorincluding at least one terminal. The probe structure includes a plungerthat includes a groove portion to which the connector is to be fitted; acoaxial probe that is inserted into the plunger and that allows aconductor pin to be exposed at a position corresponding to the terminalof the connector that is fitted into the groove portion of the plunger;and a flange that is fixed to an apparatus for inspecting thecharacteristics at a position that is spaced apart on a side opposite toa side on which the conducting pin is exposed with respect to theplunger. The flange has a through-hole into which the coaxial probe isinserted. The probe structure also includes a housing that includes afirst end portion and a second end portion and that extends toward theplunger while surrounding the coaxial probe. The first end portion isfitted into the through-hole of the flange from a side opposite to aside on which the plunger is disposed, and the second end portion isattached to the plunger. The probe structure further includes a springthat is attached to a portion between the plunger and the flange, thatis disposed at a position surrounding the housing, and that urges theplunger in a direction away from the flange. The first end portion ofthe housing and the through-hole of the flange have outer shapes thatrestrict rotation of the housing in a circumferential direction in astate in which the first end portion of the housing is fitted into thethrough-hole of the flange. With such a structure, the plunger and thehousing can rotate in accordance with the position of the terminal ofthe connector, the conductive pin of the coaxial probe can contact theterminal of the connector with high accuracy, and it is possible toimprove the reliability of the inspection of characteristics.

According to a second aspect of the present disclosure, there isprovided a probe structure according to the first aspect, in which thefirst end portion of the housing has a tapered shape that tapers inwardtoward the second end portion, and the through-hole of the flange has aninclined shape that receives the first end portion of the housing. Withsuch a structure, because a rotation-restricting mechanism of thehousing is formed by utilizing the outer shapes of the housing and thethrough-hole of the flange, it is possible to realize therotation-restricting mechanism of the housing with a simpler structurewithout providing a projection or the like.

According to a third aspect of the present disclosure, there is provideda probe structure according to the first or second aspect, in which theflange includes a projection on a surface thereof on a side thatreceives the first end portion of the housing, the projection beinglocated around the through-hole and extending toward the first endportion of the housing, and the first end portion of the housing has agroove into which the projection of the flange is fitted. With such astructure, because a rotation-restricting mechanism of the housing isformed from the groove and the projection, it is possible to morereliably restrict rotation of the housing.

According to a fourth aspect of the present disclosure, there isprovided a probe structure according to the third aspect, in which theprojection of the flange and the groove of the housing are each formedcontinuously in the circumferential direction. With such a structure, itis possible to realize a rotation-restricting mechanism of the housingwith a simpler structure than in a case where the projection and thegroove are each divided into portions that are arranged at a pluralityof positions.

According to a fifth aspect of the present disclosure, there is provideda probe structure according to the third aspect, in which the projectionof the flange and the groove of the housing are each divided intoportions that are arranged at a plurality of positions in thecircumferential direction. With such a structure, it is possible to morereliably restrict rotation of the housing.

According to a sixth aspect of the present disclosure, there is provideda probe structure according to any one of the first to fifth aspects, inwhich a wall portion of the plunger that forms the groove portionincludes a bottom wall that allows a tip portion of the conducting pinto be exposed, a first side wall that stands on a periphery of thebottom wall, and a second side wall that stands on a periphery of thefirst side wall and that is inclined so as to taper inward toward thefirst side wall. With such a structure, because the connector can bedisposed at a desired measurement position with high accuracy, it ispossible to inspect characteristics of the terminal of the connectorwith higher accuracy.

According to a seventh aspect of the present disclosure, there isprovided a probe structure according to the sixth aspect, in which aninclination angle of the second side wall is set based on a frictioncoefficient of a material of the second side wall. With such astructure, the connector can be reliably guided by the second side wall,and it is possible to further improve the positioning accuracy of theconnector.

Hereafter, embodiments of the present disclosure will be described indetail with reference to the drawings.

First Embodiment

FIGS. 1 to 3 are schematic views of a probe structure 2 according to afirst embodiment. FIG. 1 is a schematic perspective view of the probestructure 2. FIGS. 2 and 3 are partial schematic perspective views ofthe probe structure 2.

The probe structure 2 is an inspection device that is used to inspectcharacteristics of a connector (multipole connector) 3 having aplurality of terminals. The probe structure 2 includes a plunger 4,coaxial probes 6, a flange 8, a spring 10, and connectors 14.

The plunger 4 is a positioning member for positioning the connector 3 byallowing the connector 3 to be fitted thereto. The plunger 4 is made of,for example, SUS. The plunger 4 includes a fitting portion 4 a to whichthe connector 3 is fitted and a tubular portion 4 b formed in a tubularshape. The fitting portion 4 a is formed so as to protrude from an endof the tubular portion 4 b. A groove portion 22 (FIG. 3), which allowsthe connector 3 to be fitted thereto, is formed in the fitting portion 4a. The structure of the groove portion 22 and surrounding parts will bedescribed below in detail.

The plurality of coaxial probes 6 are inserted into the plunger 4. Thecoaxial probes 6 are members that contact terminals of the connector 3to be electrically connected to the terminals. Each of the coaxialprobes 6 has a bar-like shape and a tip portion thereof is exposed fromthe plunger 4.

In the present embodiment, in particular, one probe structure 2 includesthe plurality of coaxial probes 6. With such a structure, in a casewhere the connector 3, which is an inspection target, includes aplurality of terminals, it is possible to simultaneously inspectcharacteristics of the terminals of the connector 3. In the firstembodiment, an example in which the probe structure 2 has three coaxialprobes 6 will be described.

The flange 8 is used to attach the probe structure 2 to a predeterminedapparatus (such as a screening machine for screening printed circuitboards, on each of which the connector 3 is mounted, based on the resultof inspecting characteristics of the connector 3). The flange 8 is fixedto an end of the tubular portion 4 b of the plunger 4 opposite to thefitting portion 4 a.

The spring 10 is an elastic member for pressing the coaxial probes 6against the terminals of the connector 3 with an appropriate load. Thespring 10, which surrounds the tubular portion 4 b of the plunger 4, isattached to a portion between the flange 8 and the fitting portion 4 a.

The connectors 14 are used to connect the coaxial probes 6 to anexternal measurement device (not shown). The first embodiment includesthree connectors 14, which respectively correspond to the three coaxialprobes 6.

Next, referring to FIGS. 4 and 5, the coaxial probes 6 will bedescribed.

FIG. 4 is a schematic perspective view of the plurality of coaxialprobes 6 inserted into the plunger 4. FIG. 5 is a schematic perspectiveview of one of the coaxial probes 6.

As illustrated in FIGS. 4 and 5, each of the coaxial probes 6 includes aconducting pin 16 and a barrel 18.

Each of the conducting pins 16 is a bar-shaped member that contacts acorresponding one of the terminals of the connector 3 to be electricallyconnected to the terminal. The conducting pin 16 is made of anelectroconductive material so that the conducting pin 16 can beelectrically connected to the terminal of the connector 3. Theconducting pin 16 functions as a measurement pin for measuringcharacteristics of the terminal of the connector 3.

The barrel 18 is a tubular member that covers the periphery of theconducting pin 16. The barrel 18 covers the periphery of the conductingpin 16 in a state in which the barrel 18 is electrically insulated fromthe conducting pin 16. The barrel 18 is press-fitted into and fixed tothe plunger 4. The barrel 18 is made, for example, by forming goldplating on a copper-based material (such as for phosphor bronze).

Next, referring to FIG. 6, the relationship between the coaxial probes 6and the terminals of the connector 3 will be described.

As illustrated in FIG. 6, the connector 3 includes a plurality ofterminals 3 a. In the first embodiment, the connector 3 has sixteenterminals 3 a, including eight terminals 3 a that are arranged in tworows. Three coaxial probes 6 are disposed at positions corresponding tothree terminals 3 b. To be specific, when the connector 3 is disposed inthe groove portion 22, the positions of the coaxial probes 6 in theplunger 4 are set so that the tip portions of the conducting pins 16 ofthe coaxial probes 6 contact the terminals 3 b. Thus, it is possible tosimultaneously inspect characteristics of the three terminals 3 b of theconnector 3 by causing the terminals 3 b to simultaneously contact theconducting pins 16 of the three coaxial probes 6.

Next, referring to FIG. 7, the structure of the fitting portion 4 a ofthe plunger 4 will be described.

FIG. 7 is a partial longitudinal sectional view of the fitting portion 4a of the plunger 4. As illustrated in FIG. 7, the groove portion 22,which allows the connector 3 to be fitted thereto, is formed in thefitting portion 4 a of the plunger 4. Because the groove portion 22 isformed, the fitting portion 4 a has an outer shape that is inwardlyrecessed.

The groove portion 22 according to the first embodiment has a firstspace 22 a and a second space 22 b.

The first space 22 a, which is a space in which the connector 3 is to bedisposed, is formed further inward than the second space 22 b. In thefirst space 22 a, the tip portions of the conducting pins 16 of thecoaxial probes 6 are exposed.

The second space 22 b is a space that is formed further outward than thefirst space 22 a. The second space 22 b functions as a space for guidingthe connector 3 to the first space 22 a, as described below.

The first space 22 a is formed by a bottom wall 24 and a first side wall26 of the fitting portion 4 a. The bottom wall 24 is a wall of thefitting portion 4 a that forms a bottom surface of the groove portion22. The bottom wall 24 allows the tip portions of the conducting pins 16of the coaxial probes 6 to be exposed. The first side wall 26 is a sidewall standing on the periphery of the bottom wall 24. The first sidewall 26 according to the first embodiment stands perpendicular to thebottom wall 24.

The second space 22 b is formed by a second side wall 28 of the fittingportion 4 a. The second side wall 28 is a wall that stands on theperiphery of the first side wall 26. The second side wall 28 accordingto the first embodiment extends radially outward in directions away fromthe first side wall 26. In other words, the second side wall 28 has atapered shape such that the second side wall 28 is inclined so as totaper inward toward the first space 22 a. The second side wall 28,having such a shape, functions as a guide portion that guides theconnector 3 toward the first space 22 a.

Next, referring to FIGS. 8A and 8B, a method of inspectingcharacteristics of the terminals 3 b by disposing the connector 3 in thegroove portion 22 will be described.

FIGS. 8A and 8B are schematic sectional views illustrating an operationof disposing the connector 3 in the groove portion 22.

As illustrated in FIG. 8A, first, the connector 3 is moved closer to thegroove portion 22 (arrow A). Thus, the connector 3 starts to contact thesecond side wall 28 of the fitting portion 4 a (the left side in thefigure).

As described above, the second side wall 28 has a tapered shape suchthat the second side wall 28 is inclined so as to taper inward towardthe first space 22 a in the first side wall 26. Thus, the connector 3,which is in contact with the second side wall 28, is guided toward thefirst space 22 a (arrow B).

Finally, as illustrated in FIG. 8B, the connector 3 is disposed in thefirst space 22 a in the first side wall 26. The connector 3 ispositioned at a predetermined measurement position by being surroundedby the first side wall 26. At this time, the terminals 3 b of theconnector 3 are in contact with the conducting pins 16 of the coaxialprobes 6. Thus, it is possible to simultaneously inspect characteristicsof the terminals 3 b.

As described above, it is possible to simultaneously inspectcharacteristics of the plurality of terminals 3 b by causing theplurality of coaxial probes 6 to simultaneously contact the plurality ofterminals 3 b of the connector 3. Thus, it is possible to simultaneouslymeasure a plurality of signals.

To date, coaxial connectors each having only one terminal has beenmainly used to connect, for example, RF signal lines in a mobile phoneor a smartphone. In recent years, a plurality of coaxial connectors arearranged and used, because RF signals in a plurality of bands arehandled and there are a plurality of RF signal lines. As the density ofcircuits has increased, the circuits are designed so that RF singles arepassed through some terminals of a multipole connector having anirregular shape instead of using a coaxial connector.

In such circumstances, the probe structure 2 according to the firstembodiment can function as a measurement probe that can besimultaneously connected the plurality of terminals 3 b of the connector3 and can simultaneously inspect characteristics of a plurality oflines.

As described above, the probe structure 2 according to the firstembodiment, which is a probe structure for inspecting characteristics ofthe connector 3 including the plurality of terminals 3 a, includes theplunger 4 and the coaxial probes 6. The plunger 4 includes the grooveportion 22 to which the connector 3 is to be fitted. The coaxial probes6 are inserted into the plunger 4. The conducting pin 16 is disposed ata position corresponding to at least one of the plurality of terminals 3a (in the first embodiment, the three terminals 3 b) of the connector 3,which is fitted into the groove portion 22 of the plunger 4.

With such a structure, because one probe structure 2 includes theplurality of coaxial probes 6, it is possible to simultaneously inspectcharacteristics of the plurality of terminals 3 b of the connector 3,which are among the plurality of terminals 3 a. Thus, it is possible tosimultaneously measure a plurality of signals.

In the probe structure 2 according to the first embodiment, the wall ofthe plunger 4, which forms the groove portion 22, includes the bottomwall 24, the first side wall 26, and the second side wall 28. The bottomwall 24 allows the tip portions of the conducting pins 16 to be exposed.The first side wall 26 stands on the periphery of the bottom wall 24.The second side wall 28 stands on the periphery of the first side wall26 and is inclined so as to taper inward toward the first side wall 26.

With such a structure, when the connector 3 contacts the second sidewall 28, the connector 3 is guided toward the space in the first sidewall 26 and the bottom wall 24. Thus, it is possible to dispose theconnector 3 at a desired measurement position with high accuracy.Therefore, it is possible to inspect characteristics of the terminals 3b of the connector 3 with higher accuracy.

Next, referring to FIGS. 9 to 11, the probe structure 2 will bedescribed in more detail. FIGS. 9 and 10 are exploded perspective viewsof the probe structure 2. FIG. 11 is a schematic longitudinal sectionalview of the probe structure 2.

As illustrated in FIGS. 9 to 11, the probe structure 2 further includesa housing 30, a ring 32, and a plate 34, in addition to the plunger 4,the coaxial probes 6, the flange 8, the spring 10, and the connectors 14described above. The housing 30, the ring 32, and the plate 34 are notillustrated in FIGS. 1 to 8B.

The housing 30 surrounds the coaxial probes 6 and is fitted into athrough-hole 8A of the flange 8. The housing 30 has a first end portion30A (upper end portion) and a second end portion 30B (lower endportion). The first end portion 30A is fitted into the through-hole 8Aof the flange 8. The second end portion 30B is fitted into a recessedportion 4 c of the plunger 4 described above.

The first end portion 30A has a flared shape whose outer dimension inthe horizontal direction is larger than that of the second end portion30B. The shape of the housing 30 is a hollow tube that surrounds thecoaxial probes 6.

FIG. 11 illustrates a state in which the first end portion 30A of thehousing 30 is fitted into the through-hole 8A of the flange 8. Thesecond end portion 30B of the housing 30 is fitted to the plunger 4, andthe spring 10 is disposed around the housing 30 and the plunger 4. Thering 32 is disposed at a position where the spring 10 and the flange 8may contact each other. The ring 32, which is interposed between theflange 8 and the housing 30, is used to reduce friction between these.The ring 32 is made of, for example, a low-friction material such aspolyacetal (POM). The ring 32 is formed in a hollow tubular shape so asto surround the outer periphery of the housing 30.

The plate 34 is disposed in the recessed portion 4 c of the plunger 4between the second end portion 30B of the housing 30 and the plunger 4.The plate 34 can reduce occurrence of accidental removal of the coaxialprobe 6 in an upward direction.

In a state in which the second end portion 30B of the housing 30 isattached to the plunger 4 via the plate 34, the housing 30 and theplunger 4 are fitted to each other so as to be integrally rotatable inthe circumferential direction R.

In such a structure, the first embodiment is designed to allow theconnector 3 to be positioned in the groove portion 22 of the plunger 4with high accuracy. Specifics will be described with reference to FIGS.12A to 15C.

FIG. 12A is a schematic perspective view illustrating a fitted state inwhich the housing 30 and the flange 8 are fitted to each other. FIG. 12Bis a schematic perspective view illustrating an unfitted state in whichthe housing 30 has moved to a position above the flange 8 and thehousing 30 and the flange 8 are not fitted to each other. Componentsother than the housing 30 and the flange 8 are not illustrated in FIGS.12A and 12B.

In the fitted state illustrated in FIG. 12A, the first end portion 30Aof the housing 30 is fitted into the through-hole 8A of the flange 8. Atthis time, rotation of the housing 30 in the circumferential direction Ris restricted by the flange 8. To be specific, the first end portion 30Aand the through-hole 8A each have a tapered shape that tapers inward inthe downward direction. In particular, the outer periphery of each ofthe first end portion 30A and the through-hole 8A in the circumferentialdirection R has a non-circular shape. In the first embodiment, the shapeis a substantially rectangular shape with round corners when seen fromabove. With such a shape, in the fitted state in which the housing 30and the flange 8 are fitted to each other, rotation of the housing 30 inthe circumferential direction R is restricted by the flange 8. Thus, thefirst end portion 30A of the housing 30 and the through-hole 8A of theflange 8 have outer shapes that restrict rotation of the housing 30 inthe circumferential direction R in the fitted state.

The plunger 4, which is attached to a lower part of the housing 30, ispressed upward by the connector 3 in a state in which the connector 3 isdisposed in the groove portion 22. At this time, because the spring 10,which surrounds the plunger 4 and the housing 30, contracts, the housing30 moves upward relative to the flange 8 as illustrated in FIG. 12B.Thus, the first end portion 30A of the housing 30 enters an unfittedstate in which the first end portion 30A is not fitted into thethrough-hole 8A of the flange 8. In the unfitted state illustrated inFIG. 12B, the flange 8 does not restrict rotation of the housing 30, andthe housing 30 is rotatable relative to the flange 8 in thecircumferential direction R. Thus, the housing 30 and the plunger 4 canrotate in accordance with the positions of the terminals of theconnector 3. Specifics will be described with reference to FIGS. 13 to15.

FIGS. 13A to 15C schematically illustrate the positional relationshipamong components when positioning the connector 3 by disposing theconnector 3 in the groove portion 22 of the plunger 4. FIG. 13A is aschematic top view of the flange 8 and the housing 30, FIG. 13B is aschematic side view of the probe structure 2 and the connector 3, andFIG. 13C is a schematic view illustrating the rotational positions ofthe groove portion 22 of the plunger 4 and the connector 3.

FIGS. 13A-13C illustrate a state in which the probe structure 2 movescloser to the connector 3 from above. The connector 3 is fixed by a jig38. As illustrated in FIG. 13(b), because the plunger 4 is not incontact with the connector 3, the plunger 4 and the spring 10 do notreceive an upward pressing force from the connector 3. The spring 10,which does not receive a pressing force from the connector 3, urges theplunger 4 downward (arrow C), which is a direction away from the flange8. The plunger 4 and the housing 30 are urged downward by the spring 10,and the fitted state of the housing 30 and the flange 8 is maintained.Because this is the fitted state described above and illustrated in FIG.12A, rotation of the housing 30 in the circumferential direction R isrestricted. By moving the plunger 4 closer to the connector 3 in thisstate, it is possible to move the plunger 4 closer to the connector 3while fixing the rotational positions of the housing 30 and the plunger4 and to position the connector 3 with high accuracy.

As illustrated in FIG. 13C, the rotational position of the connector 3in top view does not coincide with the rotational position of the grooveportion 22 of the plunger 4.

When the plunger 4 is moved closer to the connector 3, as illustrated inFIGS. 14A-14C, the connector 3 enters the groove portion 22 of theplunger 4 and the plunger 4 contacts the connector 3. When the plunger 4is pressed downward against the connector 3, because the connector 3 isfixed by the jig 38, the plunger 4 receives an upward reactional forcefrom the connector 3 (see arrow D). Due to the reactional force, theplunger 4 is pressed upward. When the plunger 4 is pressed upward,because the spring 10 contracts as described with reference to FIG. 12B,the plunger 4 and the housing 30 move upward, and the fitted state ofthe housing 30 and the flange 8 is released. Because this is theunfitted state described above and illustrated FIG. 12B, rotation of thehousing 30 is not restricted by the flange 8, and the housing 30 becomesrotatable in the circumferential direction R.

As described above with reference to FIG. 7 and other figures, in thegroove portion 22 of the plunger 4, the second side wall 28, which is aguide portion that guides the connector 3 inward, is disposed.Therefore, when the groove portion 22 of the plunger 4 starts contactingthe connector 3, as illustrated in FIGS. 14(a) and 14(b), the plunger 4and the housing 30 rotate in the circumferential direction R so that therotational positions thereof become closer to that of the connector 3.At this time, the spring 10 and the ring 32 (FIG. 11) also rotate in thesame manner.

When the plunger 4 is further pressed against the connector 3, theplunger 4 and the housing 30 rotate further in the circumferentialdirection R and finally enter a state illustrated in FIGS. 15A-15C. Inthe state illustrated in FIG. 15C, the rotational position of the grooveportion 22 of the plunger 4 coincides with the rotational position ofthe connector 3. At this time, the three coaxial probes 6, which areexposed in the groove portion 22, are disposed at positionscorresponding to the terminals 3 b of the connector 3 and can reliablycontact the terminals 3 b. Because the coaxial probes 6 and theterminals 3 b of the connector 3 can be made to contact each other withhigh accuracy in this way, it is possible to improve the accuracy ofinspection of characteristics of the connector 3.

As described above, with the probe structure 2 according to the firstembodiment, rotation of the housing 30 is restricted in a state in whichthe housing 30 and the flange 8 are fitted to each other. On the otherhand, the restriction on rotation of the housing 30 is removed in astate in which the housing 30 and the flange 8 are not fitted to eachother. To be specific, the first end portion 30A of the housing 30 andthe through-hole 8A of the flange 8 have outer shapes that restrictrotation of the housing 30 in the circumferential direction R in a statein which the first end portion 30A of the housing 30 is fitted into thethrough-hole 8A of the flange 8. With such a structure, it is possibleto cause the coaxial probes 6 to contact the terminals 3 b of theconnector 3 with high accuracy and to improve the reliability ofinspection of characteristics.

To be more specific, because the plunger 4 is urged by the spring 10,the housing 30, which is attached to the plunger 4, is constantly urgedin a direction such that the housing 30 is fitted to the flange 8. Thus,when positioning the connector 3 in the groove portion of the plunger 4,it is possible to perform positioning in a state in which the rotationalpositions of the plunger 4 and the housing 30 are fixed. Therefore, itis possible to position the connector 3 with high accuracy. When theconnector 3 is pressed against the plunger 4 in a state in which theconnector 3 is disposed in the groove portion of the plunger 4, becausethe spring 10 contracts, the fitted state of the housing 30 and theflange 8 is released, and the plunger 4 and the housing 30 becomerotatable. Thus, the plunger 4 and the housing 30 can rotate inaccordance with the positions of the terminals 3 b of the connector 3,the coaxial probes 6 can contact the terminals 3 b of the connector 3with high accuracy, and it is possible to improve the accuracy ofinspection of characteristics.

With the probe structure 2 according to the first embodiment, the firstend portion 30A of the housing 30 has a tapered shape that tapers inwardtoward the second end portion 30B. The through-hole 8A of the flange 8has an inclined shape that receives the first end portion 30A of thehousing 30. Thus, a rotation-restricting mechanism that restrictsrotation of the housing 30 is formed by utilizing the outer shapes ofthe housing 30 and the through-hole 8A of the flange 8. With such astructure, it is not necessary to provide the flange 8 or the housing 30with a projection or the like, and it is possible to realize arotation-restricting mechanism of the housing 30 with a simplestructure.

Next, referring to FIGS. 16 and 17, the structure of the second sidewall 28, which guides the connector 3 inward in the groove portion 22,will be described.

As illustrated in FIG. 16, when the plunger 4 moves downward (see arrowE) and the connector 3 (not shown) contacts the second side wall 28 ofthe groove portion 22, the connector 3 applies an upward external forceF to the second side wall 28. The external force F can be decomposedinto a force F1 in a direction parallel to the second side wall 28 and aforce F2 in a direction perpendicular the second side wall 28. The forceF2 is received by the second side wall 28, while the force F1 serves asa driving force that slides the connector 3 along the second side wall28. In response, a frictional force X is generated along the second sidewall 28 in a direction opposite to the direction of the force F1.

In the first embodiment, in order that the connector 3 can slide alongthe second side wall 28 without fail, the inclination angle θ of thesecond side wall 28 is calculated so that the force F1 is larger thanthe frictional force X. To be specific, because the frictional force Xis determined by a friction coefficient μ, which depends on the materialof the second side wall 28, the inclination angle θ is set so as tosatisfy the relationship represented by the following Expression 1.Here, the inclination angle θ of the second side wall 28 is theinclination angle of the second side wall 28 with respect to ahorizontal plane H.

0>tan μ (rad)=(180*tan μ)/π (degrees)  (Expression 1)

FIG. 17 represents the relationship between the friction coefficient μand the inclination angle θ obtained from Expression 1. FIG. 17illustrates a line L1 corresponding to the relationship between thefriction coefficient μ and the inclination angle θ such that the forceF1 is equal to the frictional force X, which is obtained fromExpression 1. In the graph of FIG. 17, by setting an inclination angle θabove the line L1 for a certain friction coefficient μ, it is possibleto make the force F1 larger than the frictional force X without fail andto move the connector 3 along the second side wall 28 without fail.

As described above, in the probe structure 2 according to the firstembodiment, the inclination angle θ of the second side wall 28 is setbased on the friction coefficient μ of the material of the second sidewall 28. To be more specific, the inclination angle θ of the second sidewall 28 is set at an angle that is larger than a lower limit value (lineL1) that is obtained from the friction coefficient μ by usingExpression 1. By setting the angle in this way, the connector 3 can bereliably guided along the second side wall 28, and it is possible tofurther improve the positioning accuracy of the connector 3.

For example, in a case where the material of the second side wall 28 isstainless steel, the friction coefficient of the material is about 0.3.In this case, according to the graph of FIG. 17, the inclination angle θmay be set at 16.7 degrees or larger. To provide a margin, theinclination angle θ may be set, for example, at 20 degrees or larger. Ina case where the friction coefficient is 0.5, because the inclinationangle θ may be set at 26.6 degrees or larger according to the graph ofFIG. 17, the inclination angle θ may be set, for example, at 30 degreesor larger to provide a margin.

Second Embodiment

Referring to FIG. 18, a probe structure 40 according to a secondembodiment of the present disclosure will be described. The differencesbetween the second embodiment and the first embodiment will be mainlydescribed.

FIG. 18 is a schematic perspective view of a flange 42 and a housing 44of the probe structure 40 according to the second embodiment. Componentsother than the flange 42 and the housing 44 are not illustrated in FIG.18.

As illustrated in FIG. 18, the flange 42 has a through-hole 42A, and thehousing 44 is inserted into the through-hole 42A. The housing 44 has afirst end portion 44A and a second end portion 44C. A plurality ofgrooves 44B are formed in the first end portion 44A of the housing 44.In the example illustrated in FIG. 18, the grooves 44B are formed atfour positions at intervals in the circumferential direction R. Thegrooves 44B are through-holes that vertically extend through the firstend portion 44A.

The flange 42 has a plurality of projections 42C on a surface 42B on aside that receives the first end portion 44A of the housing 44. Theprojections 42C are located around the through-hole 42A. The pluralityof projections 42C are fitted into the plurality of grooves 44B of thefirst end portion 44A of the housing 44. As with the grooves 44B, theplurality of projections 42C are arranged at a plurality of positions atintervals in the circumferential direction R. In the example illustratedin FIG. 18, the grooves 44B are formed at four positions correspondingto the plurality of projections 42C at intervals in the circumferentialdirection R. In the example illustrated in FIG. 18, each of theprojections 42C has a columnar shape having a rounded tip.

When the housing 44 moves downward toward the flange 42 from the stateillustrated in FIG. 18 and the projections 42C are fitted into thegrooves 44B, rotation of the housing 44 in the circumferential directionR is restricted by the flange 42.

With the structure described above, because a rotation-restrictingmechanism of the housing 44 is formed from the grooves 44B and theprojections 42C, rotation of the housing 44 can be more reliablyrestricted. In particular, in the second embodiment, the projections 42Cof the flange 42 and the grooves 44B of the housing 44 are respectivelyarranged at a plurality of positions in the circumferential direction R.Thus, it is possible to more reliably restrict rotation of the housing44.

Third Embodiment

Referring to FIG. 19, a probe structure according to a third embodimentof the present disclosure will be described. The differences between thethird embodiment and the first and second embodiments will be mainlydescribed.

FIG. 19 is a schematic perspective view of a flange 52 and a housing 54of a probe structure 50 according to the third embodiment. Componentsother than the flange 52 and the housing 54 are not illustrated in FIG.19.

As illustrated in FIG. 19, the flange 52 has a through-hole 52A, and thehousing 54 is inserted into the through-hole 52A. The housing 54 has afirst end portion 54A and a second end portion 54C. A groove 54B isformed in the first end portion 54A of the housing 54. The groove 54B isformed continuously in the circumferential direction R. The groove 54Bis a recessed portion that is recessed inward in a lower surface of thefirst end portion 54A.

The flange 52 has a projection 52C on a surface 52B on a side thatreceives the first end portion 54A of the housing 54. The projection 52Cis located around the through-hole 52A. The projection 52C is fittedinto the groove 54B of the first end portion 54A of the housing 54. Aswith the groove 54B, the projection 52C is formed continuously in thecircumferential direction R. In the example illustrated in FIG. 19, thetip portion of the projection 52C has an inclined surface 52D that isinclined diagonally downward and outward.

When the housing 54 moves downward toward the flange 52 from the stateillustrated in FIG. 19 and the projection 52C is fitted into the grooveMB, rotation of the housing 54 in the circumferential direction R isrestricted by the flange 52.

With the structure described above, in the same way as in the secondembodiment, because a rotation-restricting mechanism of the housing 54is formed from the groove 54B and the projection 52C, rotation of thehousing 54 can be more reliably restricted. In particular, in the thirdembodiment, the projection 52C of the flange 52 and the groove 54B ofthe housing 54 are each formed continuously in the circumferentialdirection R. Thus, it is possible to realize a rotation-restrictingmechanism for the housing 54 with a simpler structure than in a casewhere the groove and the projection are each divided into portions thatare arranged at a plurality of positions, as in the second embodiment.

A part of the projection 52C that contacts the first end portion 54A ofthe housing 54 is the inclined surface 52D, which is inclined diagonallydownward. Thus, when the housing 54 moves to a position that is onlyslightly above from the flange 52, the housing 54 becomes rotatable.Thus, it is possible to further improve positioning accuracy.

Heretofore, the present disclosure has been described by using the firstto third embodiments as examples. However, the present disclosure is notlimited to the first to third embodiments. For example, each of thefirst to third embodiments includes three coaxial probes 6, andinspection of characteristics of the corresponding terminals 3 b of theconnector 3 is simultaneously performed. However, this is not alimitation. A probe structure may have one, two, four, or more coaxialprobes 6 in accordance with the number of terminals 3 a of the connector3 whose characteristics are to be inspected. The connector 3 is notlimited to a multipole connector having a plurality of terminals 3 a andmay be a monopole connector having only one terminal. That is, a probestructure may have one or more coaxial probes 6 in each of which aconducting pin 16 is disposed at a position corresponding to at leastone of the terminals 3 a of the connector 3. Also in such a case,advantageous effects that are the same as those of the embodiments canbe obtained.

In each of the first to third embodiments, the first space 22 a and thesecond space 22 b, which is inclined so as to taper inward toward thefirst space 22 a, are formed in the groove portion 22. However, this isnot a limitation. For example, the second space 22 b need not be formed.Also in such a case, it is possible to inspect characteristics of theterminals 3 b by disposing the connector 3 in the first space 22 a.However, by forming the second space 22 b that is inclined so as totaper inward toward the first space 22 a as in the embodiments, it ispossible to easily dispose the connector 3 in the first space 22 a andto improve the reliability of the inspection of characteristics of theterminals 3 b.

Although the present disclosure is sufficiently described in relation topreferred embodiments while referring to the drawings, it is clear forpersons skilled in the art that the embodiments can be modified oradjusted in various ways. Such modifications and adjustments areincluded in the scope of the present disclosure as long as themodifications and the adjustments are within the scope of the presentdisclosure. Combinations and changes in the order of components in theembodiments can be realized within the sprit and scope of the presentdisclosure.

Any of the first to third embodiments and modifications may be used inappropriate combinations to obtain the advantageous effects of theembodiments and the modifications.

What is claimed is:
 1. A probe structure for inspecting characteristicsof a connector including at least one terminal, the probe structurecomprising: a plunger that includes a groove portion to which theconnector is to be fitted; a coaxial probe that is inserted into theplunger and that allows a conductor pin to be exposed at a positioncorresponding to the terminal of the connector that is fitted into thegroove portion of the plunger; a flange that is configured to attach toan apparatus for inspecting the characteristics at a position that isspaced apart on a side opposite to a side on which the conducting pin isexposed with respect to the plunger, the flange having a through-holeinto which the coaxial probe is inserted; a housing that includes afirst end portion and a second end portion and that extends toward theplunger while surrounding the coaxial probe, the first end portion beingfitted into the through-hole of the flange from a side opposite to aside on which the plunger is disposed, the second end portion beingattached to the plunger, and the first end portion of the housing andthe flange are configured to restrict rotation of the housing in acircumferential direction in a state in which the first end portion ofthe housing is fitted into the through-hole of the flange; and a springthat is attached to a portion between the plunger and the flange, thatis disposed at a position surrounding the housing, and that urges theplunger in a direction away from the flange.
 2. The probe structureaccording to claim 1, wherein the first end portion of the housing has afirst end portion shape and the through-hole of the flange has athrough-hole shape, the first end portion shape and the through-holeshape being configured to restrict rotation of the housing in thecircumferential direction in the state in which the first end portion ofthe housing is fitted into the through-hole of the flange.
 3. The probestructure according to claim 2, wherein the first end portion shape is atapered shape that tapers inward toward the second end portion, and thethrough-hole shape is an inclined shape that receives the first endportion of the housing.
 4. The probe structure according to claim 1,wherein the flange includes a projection on a surface thereof on a sidethat receives the first end portion of the housing, the projection beinglocated around the through-hole and extending toward the first endportion of the housing, and the first end portion of the housing has agroove into which the projection of the flange is fitted.
 5. The probestructure according to claim 4, wherein the projection of the flange andthe groove of the housing are each formed continuously in thecircumferential direction.
 6. The probe structure according to claim 4,wherein the projection of the flange and the groove of the housing areeach divided into portions that are arranged at a plurality of positionsin the circumferential direction.
 7. The probe structure according toclaim 1, wherein a wall portion of the plunger that forms the grooveportion includes a bottom wall that allows a tip portion of theconducting pin to be exposed, a first side wall that stands on aperiphery of the bottom wall, and a second side wall that stands on aperiphery of the first side wall and that is inclined so as to taperinward toward the first side wall.
 8. The probe structure according toclaim 7, wherein an inclination angle of the second side wall is setbased on a friction coefficient of a material of the second side wall.9. The probe structure according to claim 2, wherein a wall portion ofthe plunger that forms the groove portion includes a bottom wall thatallows a tip portion of the conducting pin to be exposed, a first sidewall that stands on a periphery of the bottom wall, and a second sidewall that stands on a periphery of the first side wall and that isinclined so as to taper inward toward the first side wall.
 10. The probestructure according to claim 9, wherein an inclination angle of thesecond side wall is set based on a friction coefficient of a material ofthe second side wall.
 11. The probe structure according to claim 3,wherein a wall portion of the plunger that forms the groove portionincludes a bottom wall that allows a tip portion of the conducting pinto be exposed, a first side wall that stands on a periphery of thebottom wall, and a second side wall that stands on a periphery of thefirst side wall and that is inclined so as to taper inward toward thefirst side wall.
 12. The probe structure according to claim 11, whereinan inclination angle of the second side wall is set based on a frictioncoefficient of a material of the second side wall.
 13. The probestructure according to claim 4, wherein a wall portion of the plungerthat forms the groove portion includes a bottom wall that allows a tipportion of the conducting pin to be exposed, a first side wall thatstands on a periphery of the bottom wall, and a second side wall thatstands on a periphery of the first side wall and that is inclined so asto taper inward toward the first side wall.
 14. The probe structureaccording to claim 13, wherein an inclination angle of the second sidewall is set based on a friction coefficient of a material of the secondside wall.
 15. The probe structure according to claim 5, wherein a wallportion of the plunger that forms the groove portion includes a bottomwall that allows a tip portion of the conducting pin to be exposed, afirst side wall that stands on a periphery of the bottom wall, and asecond side wall that stands on a periphery of the first side wall andthat is inclined so as to taper inward toward the first side wall. 16.The probe structure according to claim 15, wherein an inclination angleof the second side wall is set based on a friction coefficient of amaterial of the second side wall.
 17. The probe structure according toclaim 6, wherein a wall portion of the plunger that forms the grooveportion includes a bottom wall that allows a tip portion of theconducting pin to be exposed, a first side wall that stands on aperiphery of the bottom wall, and a second side wall that stands on aperiphery of the first side wall and that is inclined so as to taperinward toward the first side wall.
 18. A probe structure for inspectingcharacteristics of a connector including at least one terminal, theprobe structure comprising: a plunger that includes a groove portion towhich the connector is to be fitted; a coaxial probe that is insertedinto the plunger and that allows a conductor pin to be exposed at aposition corresponding to the terminal of the connector that is fittedinto the groove portion of the plunger; a flange that is configured toattach to an apparatus for inspecting the characteristics at a positionthat is spaced apart on a side opposite to a side on which theconducting pin is exposed with respect to the plunger, the flange havinga through-hole into which the coaxial probe is inserted; a housing thatincludes a first end portion and a second end portion and that extendstoward the plunger while surrounding the coaxial probe, the first endportion being fitted into the through-hole of the flange from a sideopposite to a side on which the plunger is disposed, the second endportion being attached to the plunger; the flange includes a projectionon a surface thereof on a side that receives the first end portion ofthe housing, the projection being located around the through-hole andextending toward the first end portion of the housing, and the first endportion of the housing has a groove into which the projection of theflange is fitted; and a spring that is attached to a portion between theplunger and the flange, that is disposed at a position surrounding thehousing, and that urges the plunger in a direction away from the flange.19. The probe structure according to claim 19, wherein the projection ofthe flange and the groove of the housing are each formed continuously inthe circumferential direction.
 20. The probe structure according toclaim 19, wherein the projection of the flange and the groove of thehousing are each divided into portions that are arranged at a pluralityof positions in the circumferential direction.